code: def poly_make_valid(poly: Polygon) -> Polygon:
      """Convert a potentially invalid polygon to a valid one by eliminating
      self-crossing or self-touching parts. Note that if the input is a line, the
      returned polygon could be an empty one.
  
      Args:
          poly (Polygon): A polygon needed to be converted.
  
      Returns:
          Polygon: A valid polygon, which might be empty.
      """
      assert isinstance(poly, Polygon)
      fixed_poly = poly if poly.is_valid else poly.buffer(0)
      # Sometimes the fixed_poly is still a MultiPolygon,
      # so we need to find the convex hull of the MultiPolygon, which should
      # always be a Polygon (but could be empty).
      if not isinstance(fixed_poly, Polygon):
          fixed_poly = fixed_poly.convex_hull
      return fixed_poly
  
imports: import math
  import operator
  from functools import reduce
  from typing import List, Optional, Sequence, Tuple, Union
  import numpy
  import pyclipper
  import shapely
  from mmengine.utils import is_list_of
  from shapely.geometry import MultiPolygon, Polygon
  from mmocr.utils import bbox2poly, valid_boundary
  from mmocr.utils.check_argument import is_2dlist
  from mmocr.utils.typing_utils import ArrayLike
label_desc: Use image node_id 8 for calling a global function with example usage: poly_make_valid(poly) and returns: fixed_poly